Real cyclists don’t avoid mountains. Climbing — leg- and lung-busting as it can be — is what brings the real rewards. “It almost becomes just a battle with yourself to beat the mountain,” says Axeon Hagens Berman Cycling Team Director Jeff Louder. The only question is where to go for your next challenge? We talked to a handful of professional riders, enthusiasts, and former pros to compile a list of 23 American hill climbs every cyclist should try once. It’s a veritable Tour de Pain. So here it is, a list that is bound to leave you sore the next day, but proves you have what it takes.